Apparatus for transmitting sound in a motor vehicle

ABSTRACT

An apparatus for transmitting sound in a motor vehicle including a housing ( 1 ) with an inside partition ( 2 ), which together define or delimit two separate subspaces ( 3, 4 ), which in turn are separated by a transmission valve ( 6 ) which opens through the partition ( 2 ) and can pivot about a pivot axis ( 5 ). The first subspace ( 3 ) is connected to an intake manifold of an internal combustion engine, and the second subspace ( 4 ) is connected to an interior of the motor vehicle. An elastic and at least partially perforated sealing element ( 8 ) is provided in a gap ( 25 ) between a peripheral edge ( 7 ) of the transmission valve ( 6 ) and the housing ( 1 ).

BACKGROUND OF THE INVENTION

The present invention relates to a device for sound transmission in a motor vehicle.

The propulsion motors of modern vehicles are very smooth-running internal combustion engines which generate operating noise that is hardly audible in the interior of the vehicle. Under some circumstances, the operating noise of the internal combustion engine is audible through the secondary noise of the turning wheels, a ventilation system that is turned on, etc. Under certain circumstances, it may be desirable to audibly transmit the operating noise of the driving engine into the interior of the vehicle.

Published European patent application no. EP 1,306,829 discloses a device for transmitting the noise of an internal combustion engine in which a housing having a partition defines or delimits two separate subspaces. The partition is interrupted by a pivotable valve which separates the two subspaces. The first subspace is connected to the intake manifold of the internal combustion engine, while the second subspace leads to a wall of the vehicle or directly into the interior of the vehicle. In the first subspace, sound pressure vibrations in the intake manifold act on the half of the transmission valve which protrudes into that space and is thereby excited to execute a pivoting movement. In the second subspace, the vibrating pivoting movement of the transmission valve results in transmission of sound to the interior of the vehicle.

In an illustrative embodiment of the arrangement described above, a gap which serves to equalize static pressure differences is provided between the housing and a peripheral edge of the transmission valve. Due to the manufacturing process, the gap must have a certain width, but this has an adverse effect on the sound transmission performance. In an alternative embodiment, the gap is designed to be wider and is filled with a peripheral sealing frame. The peripheral sealing frame may have a desired damping effect on the pivoting movement of the valve. The sound transmission performance is improved by the sealing effect. The membrane-like sealing frame is subjected to high loads due to the resulting pressure differences in operation, particularly with supercharged internal combustion engines.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved apparatus for transmitting sound in a motor vehicle.

Another object of the invention is to provide a device for transmitting sound in a motor vehicle which achieves good sound transmission with a low load on the components.

These and other objects are achieved in accordance with the present invention by providing an apparatus for transmitting sound in a motor vehicle comprising a housing having an inside partition, with the housing and partition together defining two separate subspaces, and a transmission valve which opens through the partition and separates the two subspaces and which can pivot about a pivot axis; one of the subspaces being connected to an intake manifold of an internal combustion engine, and the other subspace being connected to an interior space of the motor vehicle in a manner capable of transmitting sound; wherein an elastic and at least partially perforated sealing element is arranged in a gap between a peripheral edge of the transmission valve and the housing.

In accordance with the present invention, an apparatus for transmitting sound in a motor vehicle is proposed in which an elastic sealing element that is at least partially perforated is provided in a gap between a peripheral edge of the transmission valve and the housing. The gap may have a certain width which is bridged by the sealing element. The perforations in the sealing element allow a static pressure equalization on both sides of the transmission valve, thereby reducing the static load on the transmission valve, and particularly on the sealing element. At the same time, the gap is essentially sealed with regard to dynamic pressure fluctuations due to noise, so that the sound energy is converted into a dynamically vibrating pivoting movement of the transmission valve with little or no loss. Shape and position tolerances in the gap area between the transmission valve and the housing can be compensated due to the elastic material properties of the sealing element. Only minor demands are made of the manufacturing tolerances.

In one advantageous embodiment, perforations in the sealing element are provided in the area of longitudinal edges of the transmission valve adjacent the pivot axis, while the sealing element is constructed as a membrane which is uniformly tight in the area of the end edges extending across the longitudinal edges and the pivot axis. On the end edges, the membrane-like sealing element is subject to an essentially one-dimensional bending load. This load can also be absorbed by the membrane even at high amplitudes without any risk of damage.

In addition to its sealing function, the membrane also assumes the function of a vibration damper to prevent unwanted resonant vibrations of the transmission valve. At the same time, the perforations on the longitudinal edges allow a static pressure equalization, so that the stress on the end faces of the membrane is limited to dynamic vibrating loads. The perforations may be in the form of a gap between the sealing element and the transmission valve or in the form of a slot in the sealing element. The width of the gap may advantageously be greater than or equal to zero in the neutral position of the transmission valve. In the case of mutual contact of the adjacent gap walls in the neutral position of the valve, with or without a prestress, the result is a frictional damping effect, while the gap opens in the deflected position of the transmission valve and induces a static pressure equalization.

In one advantageous embodiment, perforations are provided in corner areas of the transmission valve, and the corner areas are rounded in particular. In this way, a multidimensional spatial deformation of the sealing element with a high stress level in this area is thereby prevented.

In an area designed as a membrane, the sealing element expediently has an elastically deformable crimp beyond the perforations. The rigidity of the sealing element is reduced due to this crimp. This has hardly any adverse effect on the free oscillating movement of the transmission valve, and the sealing function is completely preserved. The crimp allows a high degree of deformation of the sealing element and thus a large movement amplitude of the transmission valve without overstressing the sealing material.

In a preferred variant, a peripheral residual gap is formed along the peripheral edge. The elastic sealing element seals the peripheral gap to a substantial extent, but not completely, and also can compensate for tolerances in position. The residual peripheral gap prevents unwanted friction and allows a certain pressure equalization and/or air exchange.

In an advantageous embodiment, the transmission valve is held pivotably on its longitudinal edges in the area of the pivot axis by two elastically rotatable axle journals. The axle journals are advantageously constructed in one piece with the sealing element, in particular with the transmission valve being held in a form-fitting manner on the axle journals. The pivotable bearing of the transmission valve results from the torsionally elastic deformability of the axle journals. Additional devices for pivotable mounting of the transmission valve are not necessary. At the same time the elastic axle journals also act as sealing elements, thereby preventing unwanted leakage in the axle area.

The transmission valve advantageously may have a web along its pivot axis with an elastic sealing strip resting on the web between the transmission valve and the partition. The elastic sealing strip may be designed to be comparatively narrow in cross section. This results in a narrow sealing contact line of the sealing strip with a comparatively high pressure per unit of surface area. In combination with the lack of a static pressure difference, a reliable seal is provided while the pivoting movement of the transmission valve is essentially unimpeded as a result of the low rigidity of the narrow sealing strip due to the narrow cross section.

The web of the transmission valve is held in particular between the elastic axle journals, forming a continuous axle element together with the axle journals. The sealing strip may be in continuous contact with the web and the axle journals, thus providing a good seal even in the corner areas and/or in the area of the axle journals.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in further detail hereinafter with reference to illustrative preferred embodiments depicted in the accompanying drawing figures, in which:

FIG. 1 is a schematic longitudinal sectional diagram of a prior art device for transmitting sound in a motor vehicle;

FIG. 2 is a perspective sectional view of an illustrative embodiment of a sound transmitting device according to the invention having a partially perforated sealing membrane extending around the periphery of the transmission valve;

FIG. 3 is a perspective overview diagram of a module composed of the transmission valve and the membrane according to FIG. 2;

FIG. 4 is a sectional diagram of the arrangement of FIG. 3 showing details of end face membrane crimps with adjacent perforations;

FIG. 5 is a sectional diagram of a variant of the arrangement of FIG. 2 with a sealing element in the form of a frame;

FIG. 6 is a perspective overview diagram of a module composed of the frame element and the transmission valve according to FIG. 5;

FIG. 7 is an enlarged detail VII according to FIG. 6 with the web held in a form-fitting manner in the axle journals;

FIG. 8 is a top plan view of the arrangement of FIG. 6;

FIG. 9 is a cross-sectional diagram of the module of FIG. 8 viewed along line IX-IX showing details of the connection between the web and the axle journals;

FIG. 10 is a longitudinal sectional diagram of the module of FIG. 8; and

FIG. 11 is an enlarged diagram of the detail XI of FIG. 10 with a gap-shaped perforation on the sealing element.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a sectional diagram depicting a prior art device for transmitting sound in a motor vehicle. The device includes a housing 1 having an inside partition 2. Housing 1 and partition 2 together define or delimit two separate subspaces 3 and 4. A part of the housing 1 is integrally molded on an intake manifold 17 of an internal combustion engine (not shown) of a motor vehicle, with the first subspace 3 being connected to the interior of the intake manifold 17 in a manner that transmits sound pressure. The partition 2 creates a fluid separation between the first subspace 3 and the second subspace 4.

A transmission valve 6 is provided which opens through the partition 2 and is mounted to pivot about a pivot axis 5 situated in the partition 2. The transmission valve 6 extends on both sides from the pivot axis 5 up to close to the inside wall of the housing 1, leaving only a narrow gap, and thereby divides the two subspaces 3, 4 into individual spaces 3′, 3″, 4′, 4″. The individual space 4″ of the subspace 4 is connected via an outlet 19 to a wall of the interior of the motor vehicle (not shown) in a manner sufficient to transmit sound pressure or is connected directly to the interior of the motor vehicle.

The transmission valve 6 is shown in its neutral position, from which it can execute an oscillating pivoting movement in the direction of double arrow 28. The pivot range is approximately 10°. The static pressure in the intake manifold 17 acts on the transmission valve 6 on both sides via the gap between the transmission valve 6 and the housing 1 in the first subspace 3 and thus does not have any effect on the deflection of the transmission valve. An oscillating sound pressure in the intake manifold 17 acts on the transmission valve 6 in the direction of arrow 18 without being able to penetrate through the narrow gap to a significant extent. Vibration is induced in the transmission valve 6 by the applied oscillating sound pressure. In the second subspace 4, the vibrating transmission valve 6 causes a similar sound pressure offset by 180° to be created in the individual space 4″ and to be rendered audible in the interior of the motor vehicle via the outlet 19.

The transmission valve 6 is supported in a fluid-tight manner in the partition 2. Due to the seal of the two subspaces 3, 4 with respect to one another in combination with the gap between the transmission valve 6 and the housing 1, the arrangement functions independently of the static pressure in the intake manifold 17 and is thus particularly suitable for use with a supercharged propulsion motor, e.g., in an intake manifold area between a turbocharger and the engine.

FIG. 2 depicts an embodiment of a sound transmitting device according to the present invention. The basic principle of this device is similar to that of the arrangement according to FIG. 1. In this device, the housing 1 consists of two housing halves 20, 21 which are bolted together through a flange 22. A membrane 27 is thereby sealingly mounted in the flange 22. The partition 2 is integrally molded in one piece on the two housing halves 20 and 21.

As shown in the sectional perspective view of FIG. 2, the transmission valve 6 is mounted to pivot about the pivot axis 5 and has a peripheral edge 7, and a gap 25 is formed between peripheral edge 7 and the inside wall of the housing 1. The gap 25 is widened at two opposing ends 11 of the transmission valve 6 and is bridged by the membrane 27. Along the longitudinal edges 10 extending perpendicular to the pivot axis 5, the gap 25 is designed to be comparatively narrow and is also bridged by the membrane 27. The peripheral membrane 27 forms a peripheral sealing element 8 which has slotted perforations 9 (described in greater detail in conjunction with FIG. 3) in the area of the longitudinal edges 10 adjacent to the pivot axis 5. In the area of the ends 11 of the transmission valve 6 extending transversely to the longitudinal edges 10 and parallel to the pivot axis 5, the membrane 27 is designed to be pressure-tight at all points and is provided with a crimp 13.

FIG. 3 shows a perspective view of a module comprised of the transmission valve 6 and the membrane 27 of FIG. 2. FIG. 3 clearly shows that the membrane 27 is constructed with a larger base area than the transmission valve 6. The membrane 27 is provided with screw holes (not shown in greater detail here) for clamping fastening in the flange 22 between the two housing halves 20 and 21 as shown in FIG. 2.

As shown in FIG. 4, the membrane 27 is constructed as a continuous, essentially flat component which is connected over its surface to the transmission valve 6. It can be seen from FIG. 3 that the membrane 27 with the crimps 13 seals the end edges 11 which extend parallel to the pivot axis 5. In the rounded corner areas 12 of the transmission valve 6, the membrane 27 is perforated. Corresponding perforations 9 continue from the rounded corner areas 12 along the longitudinal edges 10 up to the vicinity of the pivot axis 5.

In the undeflected position of the transmission valve 6 shown here, the perforations 9 in the rounded corner areas 12 are open as can be seen clearly in FIG. 4. In the vicinity of the longitudinal edges 10, the perforations 9 are formed by a slot-shaped cut in the membrane 27, and in an unloaded resting position the slit is essentially closed due to the elastic forces of the rubber-like membrane 27. The slot-shaped perforation 9 is opened only when an external pressure difference is applied or due to a pivoting deflection of the transmission valve 6.

The sectional view of FIG. 5 depicts a variant of the arrangement according to FIGS. 2 through 4, in which the peripheral edge 7 of the transmission valve 6 is secured in an annular rubber-elastic, i.e., resilient, frame 26. The frame 26 has an inside groove in which the transmission valve 6 is held in a form-fitting manner. The outer area of frame 26 is attached in a form-fitting manner in the flange 22 between the two housing halves 20 and 21. The two housing halves 20, 21 are bolted together through screw holes 29 in the flange 22 and thereby hold the frame 26. The frame 26 thus forms a sealing element 8 between the peripheral edge 7 of the transmission valve 6 and the inside wall of the housing 1.

The projecting ends of the two halves of the partition 2 are spaced a distance from the transmission valve 6, and each partition end has a groove 23 in this area. A sealing strip 16 is held in each groove 23, forming a surface sealing contact with the transmission valve 6 in the area of the pivot axis 5. The elastic design of the peripheral sealing element 8 and the sealing strips 16 permits pivoting movement of the transmission valve 6 about the pivot axis 5 in the direction of the double arrow 28. The other features and reference numerals of the arrangement according to FIG. 5 correspond to the arrangement of FIG. 2.

FIG. 6 shows a perspective view of a module comprised of the transmission valve 6 and the frame 26 according to FIG. 5. In the area of the pivot axis 5, the frame 26, which is made of a rubber elastic material, has inwardly protruding axle journals 14 integrally molded in one piece from the same elastic material, and the transmission valve 6 is mounted pivotably in the axle journals. A continuous web 15 extending along the pivot axis 5 is provided on the transmission valve 6 and transitions smoothly into the two axle journals 14. The web 15 together with the two axle journals 14 forms an axle element 31 which is continuous in the direction of the pivot axis 5.

FIG. 7 shows an enlarged detail view VII from FIG. 6 where the web 15 engages the adjacent axle journal 14 via a corresponding recess formed in a connecting section 30. The transmission valve 6 is thus mounted together with the web 15 on the two axle journals 14 in a form-fitting ir interlocking manner. It can be seen from FIG. 7 that the web 15 and the adjacent axle journal 14 lie in a common plane and form a continuous surface against which the sealing strip 16 (FIG. 5) rests to produce a seal.

FIG. 8 shows a top view of the arrangement according to FIG. 6 in which the transmission valve 6 has an essentially rectangular cross section with rounded corner areas 12. The elastic frame 26 completely encloses the transmission valve 6, thereby forming the sealing element 8. Along the peripheral edge 7 of the transmission valve 6 a peripheral residual gap 32 is formed, indicated here only as a continuous line and shown in greater detail in FIG. 11. The two axle journals 14 protrude inward from the frame 26, partially extending over the transmission valve 6 along the pivot axis 5. This illustration also shows that the contour of the web 15 transitions in a flush design into the two axle journals 14 adjacent the ends of web 15.

FIG. 9 shows a cross-sectional diagram of the arrangement according to FIG. 8 along the line IX-IX. This shows that the web 15 has an approximately semicircular protrusion on the end of each of the two connecting sections 30, which protrusions engage in a form-fitting manner in corresponding recesses in the two axle journals 14.

FIG. 10 shows a longitudinal section view of the arrangement of FIG. 8 along line X-X. As shown in FIG. 10, web 15 projects outwardly from both sides of the transmission valve 6 and forms contact surfaces for the sealing strips 16 arranged on both sides (FIG. 5). The area of the edge 11 adjacent the frame 26 is shown in an enlarged scale as detail XI in FIG. 11. The sealing element in the form of frame 26 is arranged in the gap 25 between the edge 11 of the transmission valve 6 and the housing 1 (FIG. 5), with a residual gap 32 remaining between the edge 11 and the sealing element 8.

The residual gap 32 shown here as an example for the edge 11 in combination with the sealing element 8 and the frame 26 corresponds in its design to the rounded corner areas 12 and the areas of the longitudinal edges 10. Taking into account the diagram according to FIG. 8 this yields an identical design around the entire peripheral edge 7 except for the area of the connecting journal axle 14. It may also be advantageous to construct the residual gap in the various edge areas with a differing width. The sealing element 8 may also be in contact with the edge(s) of the transmission valve 6, with or without a prestress.

The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the described embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed broadly to include all variations within the scope of the appended claims and equivalents thereof. 

1. An apparatus for transmitting sound in a motor vehicle, comprising a housing with an inside partition, said housing and partition together defining two separate subspaces, and a transmission valve which opens through the partition and separates the two subspaces and which can pivot about a pivot axis; one of said subspaces being connected to an intake manifold of an internal combustion engine, and the other subspace being connected to an interior space of the motor vehicle in a manner capable of transmitting sound; wherein an elastic and at least partially perforated sealing element is arranged in a gap between a peripheral edge of the transmission valve and the housing.
 2. An apparatus according to claim 1, wherein perforations are provided in the sealing element in the vicinity of longitudinal edges of the transmission valve adjacent the pivot axis, and the sealing element is constructed as a continuous, gas-tight membrane in the area of its end edges extending along the longitudinal edges parallel to the pivot axis.
 3. An apparatus according to claim 2, wherein the perforations are in the form of slots.
 4. An apparatus according to claim 1, wherein perforations are provided in corner areas of the transmission valve.
 5. An apparatus according to claim 4, wherein the corner areas are rounded.
 6. An apparatus according to claim 4, wherein the perforations are in the form of slots.
 7. An apparatus according to claim 1, wherein the sealing element is constructed as a continuous membrane having an elastically deformable crimp in an area inward of the perforations.
 8. An apparatus according to claim 1, wherein a residual peripheral gap is formed along the peripheral edge of the transmission valve.
 9. An apparatus according to claim 1, wherein the longitudinal edges of the transmission valve are pivotably mounted by two elastically rotatable axle journals in the area of the pivot axis.
 10. An apparatus according to claim 9, wherein the axle journals are constructed in one piece with the sealing element.
 11. An apparatus according to claim 9, wherein the transmission valve is held in a form-fitting manner in the axle journals.
 12. An apparatus according to claim 1, wherein the transmission valve has a web extending along the pivot axis of the transmission valve, and an elastic sealing strip rests against said web such that the sealing strip is situated between the transmission valve and the partition.
 13. An apparatus according to claim 12, wherein said web is disposed between the axle journals and together with the axle journals forms a continuous axle element. 